The present invention relates to a system and method for programming a mine by means of a programming device which includes a microcomputer connected to a transmitter for contactless transmission of signals for reception by a mine equipped with a receiver tuned to the transmitter for receiving the signals and connected to a microcomputer-like electronic unit in the mine.
Such mine systems and methods are known which program mines before they are laid, that is, for the normally contactless transmission of data to control desired actions within the mine after it is laid, with the data being stored in a type of data memory within the mine.
For example, German Offenlegungsschrift [laid-open patent application] No. 3,523,857 discloses a mine system of the above type in which data can be transmitted without contact from a programming device to one or a group of mines. The data are transmitted in the form of infrared signals through the intermediary of one or a plurality of input devices to an individual mine or a group of mines before they are laid and are stored in a data memory in the mine or mines. This German patent application, however, does not discuss remotely programming the mines after they are laid.
German Offenlegungsschrift No. 3,545,289 discloses a remotely programmable mine which accommodates in its mine housing a receiving unit as well as a programming unit. The mine itself includes two memories within an electronic unit, with a spoken word or sentence being stored in digitized form in the first memory when the mine is laid. A word or sentence transmitted to the mine or mines after laying is received in the mine by a receiver, is digitized and stored in a second memory and then compared with the word stored in the first memory. If there is coincidence between the words, the mine is to be secured again. The drawback of this device is the use of acoustic methods for remotely influencing the mines. It is generally known that due to the structure and operation of the human speech forming apparatus, a speaker is hardly able to pronounce the same word (or the same sentence) completely identically several times in succession, even within a short time interval, that is identical in pronunciation and inflection, etc. Thus, there inevitably exist differences between the spoken programmed word (or sentence) and the word (or sentence) transmitted later for remote actuation, particularly if this word is intended for a large number of mines and is possibly to be transmitted to the mine(s) through the intermediary of further transmitting means (e.g. a megaphone).
For a mine system according to Offenlegungsschrift No. 3,545,289 to operate in the desired manner, the accuracy of the compilation of the characteristics of the programming word must be reduced to such an extent that it considers all possible variations in the word with respect to pronunciation, inflection, etc., during the subsequent remote transmission. If, perhaps, other persons than the speaker of the programming word are to be authorized to effect a later remote actuation, the accuracy in the compilation of the word characteristics must be further reduced.
Additionally, the use of words and sentences that generally will be taken from terms originating in the programming speaker's environment, harbors the danger that these words or sentences may inadvertently be generated in another connection and possibly be detectable for the mine(s). The programmable mine system intended for later remote programming as disclosed in Offenlegungsschrift No. 3,545,289 is thus unable to meet the modern requirements for such mine systems with respect to accuracy, reproducibility and security against deception for reliable, remote programming only by friendly forces.